The present disclosure discloses methods and systems for obtaining a radiographic image. The method may include obtaining a control instruction for controlling an imaging device to image a subject; determining, based on information reflecting a user's behavior in using the imaging device, adjustment parameters of a radiation generating device in the imaging device; and based on the control instruction, determining target exposure parameters at least based on a parameter control curve or biological information of the subject, the parameter control curve including a preset first parameter control curve or a second parameter control curve determined based on operation data of the imaging device, and the biological information including at least a weight and an overall content of each component of the subject; and imaging, based on the target exposure parameters, the subject to obtain the radiographic image.